GB1582790A - Non-woven fabrics - Google Patents
Non-woven fabrics Download PDFInfo
- Publication number
- GB1582790A GB1582790A GB50216/77A GB5021677A GB1582790A GB 1582790 A GB1582790 A GB 1582790A GB 50216/77 A GB50216/77 A GB 50216/77A GB 5021677 A GB5021677 A GB 5021677A GB 1582790 A GB1582790 A GB 1582790A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fabric
- layer
- particles
- structure according
- semi
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000004745 nonwoven fabric Substances 0.000 title claims description 8
- 239000012528 membrane Substances 0.000 claims description 27
- 239000004744 fabric Substances 0.000 claims description 14
- 238000003490 calendering Methods 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 6
- 229920001169 thermoplastic Polymers 0.000 claims description 6
- 239000004416 thermosoftening plastic Substances 0.000 claims description 6
- 238000007590 electrostatic spraying Methods 0.000 claims description 3
- 239000012815 thermoplastic material Substances 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims 1
- 239000000969 carrier Substances 0.000 description 6
- 230000035699 permeability Effects 0.000 description 3
- 229920002301 cellulose acetate Polymers 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000108 ultra-filtration Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 239000012876 carrier material Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010981 drying operation Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000001223 reverse osmosis Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/10—Supported membranes; Membrane supports
- B01D69/107—Organic support material
- B01D69/1071—Woven, non-woven or net mesh
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/903—Microfiber, less than 100 micron diameter
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/27—Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
- Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
- Y10T442/608—Including strand or fiber material which is of specific structural definition
- Y10T442/609—Cross-sectional configuration of strand or fiber material is specified
- Y10T442/611—Cross-sectional configuration of strand or fiber material is other than circular
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
- Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
- Y10T442/659—Including an additional nonwoven fabric
- Y10T442/673—Including particulate material other than fiber
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Laminated Bodies (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Nonwoven Fabrics (AREA)
Description
PATENT SPECIFICATION ( 11)
1 582 790 ( 21) Application No 50216/77 ( 22) Filed 2 Dec 1977 ( 19) ( 31) Convention Application No 2 655 024 ( 32) Filed 4 Dec 1976 in ( 33) Fed Rep of Germany (DE) ( 44) Complete Specification published 14 Jan 1981 ( 51) INT CL 3 B 32 B 3/10 ( 52) Index of acceptance B 2 E 1106 1202 1205 1214 1317 1525 1724 401 U BB M ( 72) Inventors WOLFRAM SCHULTHEISS and KLAUS SCHMIDT ( 54) NON-WOVEN FABRICS ( 71) We, CARL FREUDENBERG, a German Company (a Kommanditgesellschaft, the present personally responsible partners of which are Helmut Fabricius, Hans Erich Freudenberg, Otto Schildhauer, Hermann Freudenberg, Dieter Freudenberg, and Reinhart Freudenberg) of 6940 Weinheim Bergstrasse, Hohnerweg 2, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:-
Semi-permeable membranes are employed, for example, for reverse osmosis and ultrafiltration They may take the form of, for example, tubular or flat membranes They are structurally weak and so have to be supported on a supporting element This element comprises, for example, a tube or plate that perforated or provided with channels or ducts or other means for transferring liquid through or along it Because of the high pressures that are often involved in processes using semi-permeable membranes it is necessary that the intervals between the holes, channels or ducts should be fairly large for strength reasons and so it is conventional to provide a substantially incompressible porous carrier material to serve as a drainage layer between the semi-permeable membrane and the supporting element The membrane is usually coated directly onto the carrier, and the carrier thus serves both as a drainage element and as a structural support for the delicate membrane.
It is known to use, as carriers, non-woven fabrics produced either by a dry-lay or a wetlay process or by spinning of continuous fibres, and which if necessary have been consolidated by hot calendering However, all such carriers suffer from some disadvantages.
For instance, the fibre deniers that can conveniently be utilised are rather coarse in the micro range with the result that the nonwoven fabric tends to be rather rough even after calendering, and this roughness of the carrier results in the membrane coated onto the carrier having uneven thickness, on a micro scale, and thus non-uniform properties Further, isolated fibre ends or loops generally stand out from the surface of the fabric and these thus project into the membrane and in some instances through the membrane, particularly since this is often very thin being, for example, between 50 and 500 nm in many instances.
Since these problems are particularly serious with thin membranes, attempts to overcome them involving the deposition of thicker membranes have been made Thus, for instance, the amount of cellulose acetate or other material extruded onto the carrier to form the membrane may be far above the amount that is optimum for the use of the membrane in reverse osomosis or ultrafiltration For instance, the extra thickness tends to reduce the permeation rate through the membrane, as well as to increase costs.
Thus the known non-woven carriers tend to result either in a non-uniform membrane or, if the thickness of the membrane is increased, in a membrane which is more expensive and less permeable than would be desirable.
A fibrous structure according to the invention suitable for use as a carrier for a semi-permeable membrane comprises a bonded non-woven fabric into the surface of which has been calendered an overall layer of thermoplastic particles which, before calendering, are ribbon-shaped and have a minimum dimension of 30,um, the layer having been applied by electrostatic spraying of a solution of thermoplastic material, the amount and size of the particles being such that the structure has a smoother surface than the fabric and the layer is an open layer (by which we mean that the layer is an overall or continuous layer but is sufficiently open that it does not decrease the permeability of the carrier sufficiently to detrimentally affect the permeation rate of the combination of membrane and carrier) The particles, before calendering and sometimes also after calendering, have a minimum dimension of less than 30 pm and preferably have a minimum dimension of from 1 to Co of cl 0 t 1,582,790 gm The amount of the particles applied to the fabric is generally from 1 to 200, and preferably 10 to 40, grams per square metre of the fabric.
The non-woven fabric may be formed of continuous or staple, cut and/or uncut fibres and the fibres may be inorganic or organic or a mixture thereof The fibres must be bonded to one another, either by an added bonding agent or by fusion of fusible fibres within the fabric Preferably the fabric is one that has been made by a hydrodynamic or wet-lay process using fibres including thermoplastic staple fibres and which has been preconsolidated by a drying operation, so as to cause bonding by thermoplastic fibres in the fabric.
Suitable fabrics have already been proposed for use as carriers with semi-permeable membranes but in the invention they are modified by applying the covering layer of the covering layer of thermoplastic particles and then calendering this to form the open layer The overall layer of thermoplastic particles is applied by electostatic spraying of a solution of thermoplastic material, for example by the method described in British Patent Specification No 1,346,231 The particles may be applied onto one or both surfaces of the fabric A particular advantage of the electrostatic spraying is that it can be operated to give excellent uniformity of thickness over the entire width of the fabric.
After deposition of the particles, the layer is calendered, suitably under hot calendering conditions chosen to give optimum smoothing of the surface without any substantial decrease in permeability.
By the invention it is possible to make fibrous structures suitable for use as carriers for semi-permeable membranes and which have an extremely smooth and lustrous or matt surface and which have retained substantially the porosity of the starting fabric.
The extreme uniformity of smoothness obtainable in the invention is readily perceptible, even in the micro range.
A semi-permeable membrane may then be deposited on such a fibrous structure by conventional methods, for example, by casting cellulose acetate The invention permits the formation, from membrane coating solutions, of semi-permeable membranes which are thinner than have normally been required in the past on non-woven carriers and yet which do not suffer from variations in thickness and permeability Because of the great saving in materials, both in the thickness of the membrane layer and in the elimination of the need to reject substantial parts of the coated product as unsatisfactory, which is what was required previously, the invention permits the production of supported semi-permeable membrances at reduced cost and with improved permeation rates.
Claims (6)
1 A fibrous structure, suitable for use as a carrier for semi-permeable membrane, which comprises a bonded non-woven fabric into the surface of which has been calendered an overall layer of thermoplastic particles which, before calendering, are ribbon shaped and have a minimum dimension of 30 pm, the layer having been applied by electrostatic spraying of a solution of thermoplastic material, the amount and size of the particles being such that the structure has a smoother surface than the fabric and the layer is an open layer (as hereinbefore defined).
2 A structure according to claim 1 in which the particles, before calendering, have a minimum dimension of from 1 to 201 m.
3 A structure according to claim 1 or claim 2 in which the amount of the particles applied to the fabric is from 10 to 40 grams per square metre of the fabric.
4 A structure according to any preceding claim in which the non-woven fabric was made by a wet-lay process.
A structure according to claim 1 substantially as herein described.
6 A semi-permeable membrane coated on a structure according to any preceding claim.
For the Applicants:
Gill, Jennings & Every, Chartered Patent Agents, 53 to 64 Chancery Lane, London WC 2 A 1 HN.
Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon), Ltd -1981.
Published at The Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2655024A DE2655024C3 (en) | 1976-12-04 | 1976-12-04 | Carrier layer for a semipermeable membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1582790A true GB1582790A (en) | 1981-01-14 |
Family
ID=5994679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB50216/77A Expired GB1582790A (en) | 1976-12-04 | 1977-12-02 | Non-woven fabrics |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US4180611A (en) |
| JP (1) | JPS5370987A (en) |
| AT (1) | AT367313B (en) |
| AU (1) | AU512500B2 (en) |
| CA (1) | CA1098771A (en) |
| DE (1) | DE2655024C3 (en) |
| DK (1) | DK148436C (en) |
| ES (1) | ES463359A1 (en) |
| FR (1) | FR2372644A1 (en) |
| GB (1) | GB1582790A (en) |
| IL (1) | IL53456A0 (en) |
| NL (1) | NL184798C (en) |
| SE (1) | SE433507B (en) |
| ZA (1) | ZA776020B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2169224A (en) * | 1984-12-21 | 1986-07-09 | Pall Corp | Supported microporous membranes |
| US4774001A (en) * | 1984-12-21 | 1988-09-27 | Pall Corporation | Supported microporous membrane |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3174809D1 (en) * | 1980-09-11 | 1986-07-17 | Atomic Energy Authority Uk | Selective retention with composite materials |
| GB2134808B (en) * | 1983-01-24 | 1987-08-05 | English Clays Lovering Pochin | Pressure filters |
| JPS61222506A (en) * | 1985-03-29 | 1986-10-03 | Japan Vilene Co Ltd | Semipermeable membrane support and its preparation |
| US4714647A (en) * | 1986-05-02 | 1987-12-22 | Kimberly-Clark Corporation | Melt-blown material with depth fiber size gradient |
| US4904523A (en) * | 1987-01-06 | 1990-02-27 | Pellon Company | Polyester heat bonded product |
| US5391425A (en) * | 1992-07-30 | 1995-02-21 | Hexcel Corporation | Composite material with shrinkage barrier |
| JP5291274B2 (en) * | 2000-09-22 | 2013-09-18 | 阿波製紙株式会社 | Semipermeable membrane support and method for producing a semipermeable membrane using the same |
| DE102007042554B4 (en) * | 2007-09-07 | 2017-05-11 | Carl Freudenberg Kg | Nonwoven with particle filling |
| KR101298120B1 (en) * | 2008-02-20 | 2013-08-20 | 칼 프로이덴베르크 카게 | Nonwoven fabric having cross-linking material |
| JP5216924B1 (en) * | 2012-01-30 | 2013-06-19 | 北越紀州製紙株式会社 | Nonwoven fabric for semipermeable membrane support |
| JP5203518B1 (en) * | 2012-03-01 | 2013-06-05 | 北越紀州製紙株式会社 | Nonwoven fabric for semipermeable membrane support and method for producing the same |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB776179A (en) * | 1954-09-24 | 1957-06-05 | Celanese Corp | Plastic laminates |
| US3102836A (en) * | 1959-10-20 | 1963-09-03 | United Shoe Machinery Corp | Sheet material comprising fibers and plastic particles |
| US2992149A (en) * | 1960-03-23 | 1961-07-11 | Chicopee Mfg Corp | Heat-sealable sheet materials |
| NL6403128A (en) * | 1963-10-31 | 1965-05-03 | ||
| US3503784A (en) * | 1965-10-15 | 1970-03-31 | Kuraray Co | Smooth surfaced sheet materials and method of manufacturing the same |
| GB1159997A (en) * | 1966-08-23 | 1969-07-30 | August Ferdinand Junio Schramm | Processes of Making Flexbiel Air-Permeable Sheet Products |
| GB1241973A (en) * | 1968-07-30 | 1971-08-11 | American Standard Inc | Improvements in or relating to supporting osmotic membranes |
| NL7102636A (en) * | 1971-02-26 | 1972-08-29 | Reverse osmosis appts - with open celled synthetic resin layer between cellulose acetate membrane and plastic support tube | |
| US3762566A (en) * | 1971-08-03 | 1973-10-02 | Abcor Inc | Supported semipermeable membranes and process for preparing same |
| NL7301642A (en) * | 1972-02-07 | 1973-08-09 | ||
| US3837995A (en) * | 1972-04-24 | 1974-09-24 | Kimberly Clark Co | Autogenously bonded composite web |
| FR2194461B1 (en) * | 1972-06-23 | 1975-03-07 | Rhone Poulenc Ind | |
| US3878014A (en) * | 1973-04-30 | 1975-04-15 | Beloit Corp | Process for matting melt blow microfibers |
| US3914358A (en) * | 1973-12-10 | 1975-10-21 | Westinghouse Electric Corp | Method of improving the finish of the bores of a reverse osmosis sand module |
| US3949130A (en) * | 1974-01-04 | 1976-04-06 | Tuff Spun Products, Inc. | Spun bonded fabric, and articles made therefrom |
-
1976
- 1976-12-04 DE DE2655024A patent/DE2655024C3/en not_active Expired
-
1977
- 1977-10-07 ZA ZA00776020A patent/ZA776020B/en unknown
- 1977-10-19 ES ES463359A patent/ES463359A1/en not_active Expired
- 1977-10-20 AU AU29899/77A patent/AU512500B2/en not_active Expired
- 1977-11-03 NL NLAANVRAGE7712122,A patent/NL184798C/en not_active IP Right Cessation
- 1977-11-11 JP JP13484477A patent/JPS5370987A/en active Granted
- 1977-11-23 IL IL53456A patent/IL53456A0/en not_active IP Right Cessation
- 1977-12-01 US US05/856,564 patent/US4180611A/en not_active Expired - Lifetime
- 1977-12-01 SE SE7713647A patent/SE433507B/en not_active IP Right Cessation
- 1977-12-02 GB GB50216/77A patent/GB1582790A/en not_active Expired
- 1977-12-02 DK DK539777A patent/DK148436C/en not_active IP Right Cessation
- 1977-12-02 FR FR7736384A patent/FR2372644A1/en active Granted
- 1977-12-02 AT AT0865877A patent/AT367313B/en not_active IP Right Cessation
- 1977-12-05 CA CA292,368A patent/CA1098771A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2169224A (en) * | 1984-12-21 | 1986-07-09 | Pall Corp | Supported microporous membranes |
| US4774001A (en) * | 1984-12-21 | 1988-09-27 | Pall Corporation | Supported microporous membrane |
Also Published As
| Publication number | Publication date |
|---|---|
| IL53456A0 (en) | 1978-01-31 |
| AT367313B (en) | 1982-06-25 |
| SE433507B (en) | 1984-05-28 |
| DK148436B (en) | 1985-07-08 |
| NL7712122A (en) | 1978-06-06 |
| JPS5370987A (en) | 1978-06-23 |
| DK539777A (en) | 1978-06-05 |
| AU2989977A (en) | 1979-04-26 |
| ZA776020B (en) | 1978-05-30 |
| DE2655024B2 (en) | 1981-06-04 |
| ES463359A1 (en) | 1978-07-16 |
| DE2655024C3 (en) | 1982-04-22 |
| NL184798C (en) | 1989-11-01 |
| FR2372644B1 (en) | 1984-09-14 |
| ATA865877A (en) | 1981-11-15 |
| US4180611A (en) | 1979-12-25 |
| DE2655024A1 (en) | 1978-06-08 |
| AU512500B2 (en) | 1980-10-16 |
| FR2372644A1 (en) | 1978-06-30 |
| JPS6158203B2 (en) | 1986-12-10 |
| CA1098771A (en) | 1981-04-07 |
| SE7713647L (en) | 1978-06-05 |
| DK148436C (en) | 1986-03-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19921202 |